Substituted-3-oxo-butanoyl-cyclohexenes

ABSTRACT

New alicyclic ketones useful for perfumery and flavour industry and process for preparing same. Use of said compounds as perfuming and/or flavouring ingredients in the manufacture of perfumes and perfumed products and/or in the preparation of artificial flavours for foodstuffs, beverages, animal feeds, pharmaceutical preparations and tobacco products.

United States Patent Schulte-Elte 1 Dec. 2, 1975 [54] SUBSTlTUTED-3-OXO-BUTANOYL- 2,742,503 4/1956 Hansley 260/586 R CYCLOHEXENES 2,773,099 12/1956 Stork 260/586 R 3,268,589 8/1966 Rowland 260/617 C X Inventor: Karl-Heinrich schulte-Elte, Onex, 3,499,938 3 1970- Hwang eta]. 260/617 c Geneva Switzerland OTHER PUBLICATIONS [73] Assignee: g Geneva Salomaa, The Chem. of the Carbonyl Group, pp.

202-204, 1966. [22] Filed Mar. 30,1973 Schreiber et al., Helv. Chim. Acta, Vol. 50, pp. 21 Appl. N6; 346,296 21014108 (196 Weygand et al., Preparative Orgamc Chem1stry, pp.

' 70-74 (1972). [30] Foreign Application Priority Data Mar. 30, 1972 Switzerland 4770/72 P i Examiner-Norman Morgenstern Attorney, Agent, or Firm--Pennie & Edmonds [52] US. Cl 260/586 R; 131/17; 252/522;

260/307 R; 260/563 R; 260/566 A; 260/566 57 ABSTRACT F; 260/586 C; 260/586 P; 260/617 R; 1

26O/617 C; 426/171; 426/175 New alicychc ketones useful for perfumery and fla- 51 rm. c1. c07c 49/61 industry and Pmcess Preparing Same Use of [58] Field of Search 260/5 86 R, 587, 617 c Said compounds as pe fumin and/or flavouring ingre- 1 dients in the manufacture of perfumes and perfumed [56] References Cited products and/or in the preparation of artificial fla- UNITED STATES PATENTS vours for foodstuffs, beverages, animal feeds, pharma- 2 449 956 9/l948 sh k l 1 260/586 ceutical preparations and tobacco products.

0 a eta. R X r 2,507,647 4 Claims, 'No Drawings 5/1950 Robeson et al. 260/586 R X 1 SUBSTITUTED-3OXO-BUTANOYL-CYCLOHEX- ENES SUMMARY OF THE INVENTION This invention relates to unsaturated alicyclic ketones having valuable organoleptic properties and useful for perfuming and flavouring a wide range of compositions. The compounds of the present invention may be compounded with other odoriferous compounds, to make perfumery compositions, in a manner conventional in the perfumery art; they may be used, combined with carriers or diluents, for perfuminga wide range of products, and they may also be used to modify the organoleptic properties of foodstuffs, animal feeds, beverages, phamaceutical preparations and tobacco products.

The compounds to which the present invention relates have the formula:

indexes m and n both stand for zero or 1;

the ring contains the double bond in position 1, 2

(endocyclic or exocyclic), 3 or 4, or two conjugated double bonds in positions 1 and 3;

the side-chain at position 1 of the ring can contain a double bond in position 2 or 3' as indicated by the dotted lines;

R and R both represent hydrogen or one of them represents a lower alkyl containing from 1 to 6 carbon atoms and the other hydrogen;

R R and R all represent hydrogen or one of them represents a lower alkyl containing from 1 to, 6 carbon atoms and the others hydrogen; and

X represents oxygen (when m zero and n l), or

a hydroxyl radical (when m=n=zero);

but 1-yl]-cyclohex-2-ene, which has been described in l-lelv. Chim. Acta, 50, 2101 (1967), the compounds of formula I are new and belong to a class of ketone derivatives which in accordance with the present invention are prepared by:

a. subjecting to a hydrolysis a compound of formula BACKGROUND OF THE INVENTION Although the structure of ketones l is rather similar to that of the ionones or to that of the ketone compounds described in particular in l-lelv. Chim. Acta, 53, 541, (1970), especially damascenone,

damascenone ionones we have surprisingly found that odoriferous and flavouring characteristics of the compounds of the present invention are clearly different from those shown by the analogous compounds referred to. This fact illustrates once more the feature of surprise which is generally connected to the phenomena of olfactive and gustative perception. Indeed, we must stress the fact that in spite of the great number of theories hitherto developed in order to define the detection of the specific sig- .naling obtained in the presence of a particular chemical compound, we must admit that at the present state of knowledge there is no theoretical relationship which would enable to predict with certainty the odour or the taste of a given chemical compound.

Whereas the ionones have a typical and intense odour of violets [see for example: P. '2. Bedoukian,

Perfumery and Flavouring Synthetics, 'Elsevier Publ. Co. (1967) and Fortschritte der Chemie organischer Naturstoffe, Vlll, M6 (1951)] and the unsaturated ketone compounds of the damascenone type [see: Helv. Chim. Acta, 53, 541 (1970)] are odoriferous constituents of distilled Bulgarian rose oil, we have now found that the diketone or keto-hydroxyl compounds of formula I ,develop a mint-like, slightly musky odour which is sometimes reminiscent of aromatic herbs such as marjoram.

The novel compounds disclosed in the present application namely include the compounds of the formula R con C(H) H R l n m 2 2 I R l wherein:

indexes m and n stand for zero or i; the ring contains one double bond in position 1, 2 (exocyclic), 3 or 4, or two conjugated double bonds in positions 1 and 3; the side-chain at position 1 of the ring can contain 3 a double bond in position 2' or 3 as indicated by the dotted lines; Y R and R both represent hydrogen or one of them represents a lower alkyl containing from 1 to 6 carbon atoms and the other hydrogen; R R and R all represent hydrogen or one of them represents a lower alkyl containing from 1 t0 6 carbon atoms and the others hydrogen; and X represents oxygen (when m zero andn l), or

a hydroxyl radical (when m=n=zero); 10 B:

m=n=l; the ring contains a double bond in position 1, 2 (endocyclic), 3 or 4, or two conjugated double bonds in position 1 and 3; the side-chain at position 1 of the ring can contain a double bond in position 2 as indicated by the dotted lines: R, R R, R and R have the same meaning as that indicated above;

PREFERRED EMBODIMENTS OF THE INVENTION Depending upon the nature of the products into which compounds I or theabovecited derivatives are incorporated or that of the other constituents present in an odoriferous or flavouring composition and de-.

pending on the concentrations at which they are used, they can develop odoriferous and gustative notes such as animal, fruity, herb-like notes or various combinations of such notes; and they are sometimes reminiscent of the taste and flavour of certain tobaccos. Therefore, compounds of formula I can be used as perfuming ingredients for the preparation of perfumes and perfumed products.

Particularly, compounds I and the above cited derivatives are interesting ingredients for the preparation of perfume compositions, e.g. of the Chypre type, and for the reconstruction of various artificial essential oils.

The cited compounds also possess very interesting flavouring properties and consequently, can be used as flavouring agents or as additives destined to modify the organoleptic properties of foodstuffs, animals feeds, beverages, pharmaceutical preparations and tobacco. They can develop floral, ,camphor-like, woody notes and they are sometimes reminiscent of the odour and taste of certain berries, e.g. bilberries.

The term foodstuff is used broadly herein; the compounds of the invention may be incorporated into products such as tea, coffee and cocoa.

The proportions of the said compounds to be used in order to achieve an interesting odoriferous or gustative effect vary within a wide range. For example in the preparation of perfume compositions, interesting effects can be obtained when the compounds of the invention constitute as little as 500 ppm. of the total weight of the perfumed composition, or as much as 5 or even 10 of the total composition, particularly when special odoriferous effects are sought.

Similarly, the proportions used for flavouring purposes can also vary widely. Typically, interesting flavouring effects can be achieved with amounts ranging from about 0.1 to about 10 ppm, based on the total weight of the product flavoured. However, these proportions can be raised beyond the indicated limits; in admixture with other flavouring agents, they may typically be comprised from 0.5 to 15 of the total weight of the composition.

According to a preferred mode of execution of the process of the present invention the hydrolysis of compounds [1 is carried out by means of an acidic agent, e.g. a strong mineral acid. A hydrogen halide, e.g. hydrochloric or hydrobromic acid, or sulphuric or phosphoric acid can be used. Suitable acidicreagents include organic acids, e.g. p-toluene-sulphonic or formic acid; hydrochloric acid is however preferred. The hydrolysis is preferably performed in an aqueous medium in the presence of an inert organic solvent. Suitable solvents include common organic solvents such as alcohols, e.g. methanol, ethanol or isopropanol, or ethers such as dioxan, tetrahydrofuran or monoglyme, or a mixture of at least two of the said solvents. Aqueous methanol is preferred.

The said hydrolysis may occur in a wide temperature range. The formation of compounds I' was observed at temperatures from about 15 to about C, however, it has been observed that the best yields of final product are obtained when the hydrolysis is performed at a temperature in the vicinity of the boiling temperature of the selected solvent.

The process of the invention is illustrated by the following reaction scheme:

Ilb

hydrolysis =C CH R (i) and (ii) represent imino-amino and ketal-enol equilibrium reactions, respectively.

By reduction of the obtained compounds l'a, l'b or Ic, in particular those which contain a single double bond in position 1 or 2 of the ring, compounds of for mula group present in the molecule whereby dihydroxyl compounds having the fonnula are obtained.

It has been observed that the best yields of hydroxyketone I B are reached when the reduction is carried out in a neutral or slightly alkaline medium.

The compounds of formula II, used as starting materials in the process of the invention, can be prepared according to the synthetic method described in our copending application No. 343,490 filed Mar. 21, 1973. The said method can be illustrated by the following reaction scheme:

SCHEME A:

NH OH.HCl

Apart from being useful in their own right by virtue of their valuable organoleptic properties, the compounds of formula I are also useful as intermediates in the preparation of compounds of formula III The said dehydration is preferably effected by means of an acidic or basic agent or by the action of heat. Suitable dehydration reagents include mineral acids, such as sulphuric, hydrochloric, boric or phosphoric acid, or

SCl-IEME- 1a an organic acid, such as p-toluenesulphonic acid. Oxides, e.g. phosphoric acid anhydride, or organic acid anhydrides, e.g. acetic anhydride, can also promote the said dehydration.

Strong bases can also be used. In this case, however, there were obtained secondary products, probably formed by reactions other than the mere dehydration.

The above described conversion of compounds 1 into compounds 111 represents a technically original solution of the problem brought up by the synthesis of unsaturated alicyclic ketones 111. Most of these compounds and various processes for their preparation have been described in the past. The synthetic methods used heretofore for the preparation of such compounds include:

a. partial hydrogenation of the corresponding acetylenic derivatives [Swiss Pat. No. 498,795];

b. direct condensation of an organo-metallic propene derivative with a cyclogeranoyl derivative [Swiss Pat. No. 503,684];

c. cyclization of a pseudo-ketone by means of an acidic cyclization agent [Swiss Pat. No. 503,685];

d. dehydrogenation of a cyclohexenic ketone to ob-.

tain the corresponding cyclohexadienic derivative [Swiss Pat. No. 505,773].

The above indicated conversion has the advantages of affording better yields and using more readily accessible starting materials than the earlier processes.

The compounds of formula 1 comprising an exocyclic double bond in the ring can be converted into their corresponding saturated derivatives by means of the reduction techniques conventional in the art. The hereinbelow scheme will illustrate various reactions to which compounds I and some of their derivatives may undergo.

1. NaOCH 2. c5 1 on 9 Q" H-CI-l-CH-Cl-l 00 ca co CH3 Nam, co c m (ll-l CH3 LiAlHu (5H 3 CH3 I (31-13 \I 3 9H 1H co-ca -co-crr Ram -cn -co-ca MAM ca-ca -ca-cn 9 I co-ca CO-CH 2 3 LlAlH CH 2 CH 3 The above scheme is intended to serve as an example.

The invention is illustrated by the following examples, in which all the temperatures are indicated in de grees centigrade and the abbreviations have the meaning conventional in the art.

EXAMPLE 1 2,6,6-Trimethyl-1-[ l ,3-dioxo-but- 1 -yl]-cyclohex-2-ene 23 g of 2,6,6trimethyl-1-[3-amino-but-2-en-l-oyl]- cyclohex-Z-ene in 150 ml of methanol were kept at reflux for 4 hours in the presence of 110 ml of a 10 aqueous solution of hydrochloric acid in water. After cooling the reaction mixture was extracted with ether (4 fractions of 100 ml each), and the combined organic extracts were washed with a sodium bicarbonate solution until neutrality. After concentration under reduced pressure, the fractional distillation of the residue provided 21 g (yield 92 of the desired diketone; b.p. 62-65/0.01 Torr.

1R 2900, 1610 cm NMR 0.9 and 0.94 (6H, 25); 1.6 (3H, broad band, s): 2.02 (31-1, s); 5.4 (11-1, s); 5.52 (1H, m) 6 ppm MR: M =208 (6); m/e: 175 (0.1); 150 (3); 135 (1); 124 (8); 109 (18); 85 (100); 69 (3); 55 (3); 43 (25); 27 (18).

The 2 ,6,6-trimethyll-[3-amino-but-2-enl -oyl]- cyclo-hex-Z-ene, used as starting material in the above indicated preparation, can be prepared as follows:

a. 77 g of hydroxylamine hydrochloride and 125 g of anhydrous sodium acetate in 200 ml of water were added to a solution of 200 g of a-ionone in 500 m1 of ethanol. The reaction was slightly exothermic and the temperature rose to about 35. After stirring of the reaction mixture for minutes, the volatile portions were distilled off under reduced pressure. The residual aqueous solution was then diluted with 200 ml of water and extracted with two fractions of 150 ml each of petroleum-ether (b.p. 80100). The combined organic extracts were washed with water and a 10 diluted solution of sodium hydrogenocarbonate until neutrality. The evaporation of the volatile portions resulted in a residue constituted by 0t-10fl0116 oxime (210 g). An analytical sample was prepared by purification by means of thin layer chromatography.

b. A solution of 88.9 g of sodium hydrogenocarbonate in 750 ml of water was added, while stirring to a solution of 53.0 g of a-ionone oxime (0.260 mole) in 750 ml of tetrahydrofuran.

The process was then carried on in the absence of light, and a solution of 148.6 g of potassium iodide and 69.2 g of iodine (0.270 mole) in 500 ml of water was added. After refluxing for 7 hours, the solution was allowed to stand overnight. After dilution with 500 ml of a concentrated solution of sodium bisulphite in water, the reaction mixture was extracted with ether (750 ml) and the combined organic extracts were dried over anhydrous sodium sulphate and concentrated under reduced pressure. Distillation of the thus obtained residue yielded 28.75 g of 3-methyl-5-[2,6,6-trimethylcyclohex-2-en-1-yl]-isoxazole with a yield of 54 B.p. 69-70/0.04 Torr.

1R (CHCI 2960, 1595, 1445, 1415 cm NMR (CDCl 0.73 (3H, s); 0.99 (3H, s); 1.55 (3H, m); 2.22 (31-1, s); 2.92 (11-1, broad band, s); 5.49 (11-1, m); 5.68 (1H, s); 1.2-2.2 (41-1, multiplet) 8 ppm UV (95 ethanol) nm max 218 (e 9750).

MS (70 eV) 1V1 205.

c. 4.10 g (0.020 mole) of 3-methyl-5-[2,6,6-trimethyl-cyclohex-2-en-l-yl]-isoxazole were dissolved in 5 ml of anhydrous ethanol and the solution was added to 0.173 g of a mixture of 83.6 of platinum oxide in 30 ml of ethanol, the said mixture having previously been subjected to a hydrogenation. The solution was then subjected to a hydrogenation. The solution was then subjected to a hydrogenation at room temperature and at atmospheric pressure and, after absorption of one equivalent of hydrogen, filtered through aCe1ite carrier. After having been concentrated under reduced pressure the residual solution was subjected to chromatography on a magnesium silicate column by elution with a mixture of chloroform/hexane 25/75) to yield 3.73 g (yield: of 2,6,6-trimethyl-1[3-amino-but- 2--en-1-oyl]-cyclohex-2-ene.

IR (Cl- (31 3485, 2950, 1615, 1590, 1520 cm NMR (CDC1 0.89 (61-1, s); 1.58 (31-1, m); 1.90 (31-1, s); 2.38 (11-1, broad band, 5); 5.06 (1H, broad band, s); 5.50 (11-1, m); 1.22.3 (41-1, multiplets) Sppm UV ethanol) nm max 301 (6 18,400)

MS (70 eV) 1V1 207.

2,6,6-Trimethyl-1-[3-hydroxy-butan-1-oy1]-cyc1ohex- 2-ene a. by catalytic hydrogenation 4.16 g (0.02 mole) of the diketone prepared as described above in 50 ml of methanol were subjected to a hydrogenation in the presence of about 0.5 g of Raney nickel and of a small amount of KOl-l. After absorption of about 450 ml of hydrogen the said absorption proceeding within about 20 hours the reaction mixture was filtered, the volatile portions were evaporated and the residue was first taken up in petroleum-ether, then washed with water and sodium bicarbonate until neutrality. Distillation gave 3.6 g of an oil which, by separation by means of vapour phase chromatography, yielded 3.1 g (yield 74 of the desired hydroxyketone.

IR 3450 and 1705 cm NMR 0.9 (6H, s); 1.09 (3H, d, J=7 cps); 1.6 (3H, m); 2.6 (1H, s); 4.0 (11-1, m); 5.5 (11-1, m) 8 ppm MS M =210 m/e: 192 (2); 166 (3); 151 (0.5); 135 (0.5); 123 (85 109 (8); 87 (60); 69 (61); 55 (5); 43 (100); 29 (5).

By separation by means of a vapour phase chromatography there was also obtained 0.5 g of 2,6,6-trimethyll-[ 1,3-dihydroxy-but-1 -yl]-cyclohex-2-ene.

b. by reduction by means of LiAlI-L,

1.6 g of the diketone prepared as described above in 50 ml of ether were treated, while stirring and cooling, with 0.4 g of lithium-aluminium hydride in 30 ml of ether. 5 minutes are needed to complete the addition of LiAl1-1 Then methanol and water were added to the reaction mixture which was afterwards extracted with ether. After separation, the combined organic extracts were washed with water, neutralized with a solu tion of sodium bicarbonate and finally the volatile portions were evaporated. The resulting residue was distilled to give 1.5 g of a mixture containing 35 of the desired hydroxyketone. 2,6,6-Trimethyl-l-[3-hydroxy-butan-1-oyl]-cyclohex- 2-ene can be converted into 2,6,6-trimethyl-[but-2-en- 1-oyl]-cyclohex-2-ene as follows:

1.0 g of 2,6,6-trimethyl-l-[3-hydroxy-butan-1-oyl]- cyclohex-2-ene, in about 25 ml of methylene chloride, was heated for 60 minutes at about 40 in the presence of a small amount of p-toluenesulphonic acid. After extraction with ether the combined organic extracts were washed with a 10 sodium bicarbonate solution and then with water. After drying over anhydrous MgSO the evaporation of the ether gave a residue which, after distillation, yielded the desired ketone, (yield 90 The analytical data were identical with those of a pure sample prepared according to one of the known methods [cf. Swiss Pat. No. 503,685].

EXAMPLE 2 2,6,6-Trimethyl-[ 1,3-dioxo-butl -yl]-cyclohex- 1 -ene 30 g of 2,6,6-trimethyl-1-[3-amino-but-2-en-l-oyl]- cyclohex-l-ene in 150 ml methanol were reacted at room temperature with 130 ml of a 10 solution of phosphoric acid. The complete conversion of the starting material took place within 12 hours. After cooling the mixture was taken up with petroleum-ether and the organic petroleum-ether extracts were washed with water until neutrality. After concentration under reduced pressure, the residue obtained gave by fractional distillation 28.5 g (yield 95 of the desired diketone b.p. 757/0.15 Torr; n,, 1.5141, d 1.004

1R 2600, 1610 cm' NMR: 1.05 (6H, 2s); 1.65 (3H, s); 2.05 (3H, s); 5.3 (1H, s) 8 ppm MS: M* 208 (12); m/e: 193(100), 175(5); 165 (7); 150(10); 135 (16); 123 (16); 109 (16);91 (5); 85 (32); 69 (5); 55 (5); 43 (40); 27 (4).

The 2.6,6-trimethyl-1-[3-amino-but-2-en-1-oyl]- cyclohex-l-ene used as starting material in the above indicated preparation can be prepared as follows:

a. 77 g of hydroxylamine hydrochloride and 125 g of anhydrous sodium acetate in 200 ml of water were added to a solution of 200 g of B-ionone in 500 ml of ethanol. The reaction was slightly exothermic and the temperature rose to about 35. The reaction mixture was stirred for 15 more minutes and the volatile portions were distilled off under reduced pressure. The residual aqueous solution was then diluted with 200 ml of water and extracted with two fractions of 150 ml each of petroleum-ether (b.p. -100). The combined organic extracts were washed with water and a 10 diluted solution of sodium hydrogenocarbonate until neutrality. The evaporation of the volatile portions resulted in a residue constituted by the desired B-ionone oxime (210 g.) An analytical sample was prepared by purification by means of thin layer chromatography. The obtained product had a b.p. of /0.001 Torr.

b. A solution of sodium hydrogenocarbonate (136 g) in 1300 ml of water was added, whhile stirring, to a solution ofB-ionone oxime (85 g; 0.410 mole) in 1500 ml of tetrahydrofuran.

The process was then carried on in the absence of light, and a solution of potassium iodide (235 g; 1.41 moles) and iodine (109 g; 0.43 mole) in 1000 ml of water was added. After having been refluxed for 4 hours, the solution was allowed to stand overnight. After dilution with 1500 ml of a concentrated solution of sodium bisulphite in water the reaction mixture was extracted with ether (3 liters) and the combined organic extracts were dried over anhydrous sodium sulphate and concentrated under reduced pressure. The fractional distillation of the thus obtained residue yielded 77.2 g g of 3-methyl-5-[2,6,6-trimethylcyclohex-1-en-1-yl]-isoxazole (yield 91 b.p. 70-7l/0.03 Torr.

IR (CHC1 2930, 1655, 1585, 1410 cm NMR (CDCl 1.00 (61-1, s); 1.50 (3H, s); 2.27 (31-1, s); 5.86 (11-1, s); 1.5 2.2 (61-1, multiplets) 8 ppm UV (95 ethanol) nm max 209, 224

MS (70 eV) M 205.

30.75 g (0.15 mole) of 3-methy1-5-[2,6,6-trimethylcyclohex-l-en-l-yl]-isoxazole were dissolved in 50 ml of dry ethanol and the solution was added to 1.396 g of i a mixture of 82,9 of platinum oxide in 600 ml of ethanol, the said mixture having previously been subjected to a hydrogenation. The alcoholic solution was then subjected to a hydrogenation at ordinary temperature and pressure and, after absorption of one equivalent of hydrogen, was filtered through a Celite carrier. After having been concentrated under reduced pressure, the residual mixture was recrystallized from hexene containing traces of ethanol to yield 30.91 g (yield of 2,6,6-trimethyl-1-[3 -amino-but-2-enoyl ]-cyclohexl-ene which exists in two interconvertible crystalline structures: m.p. 124.5125.0 and 136.

IR (CHCI 3490, 1610, 1510 cm NMR(CDC1 1.09 (6H, s); 1.56 (3H, s); 1.92 (3H, s); 5.00 (1H, broad band, 5); 1.42.1 (61-1, multiplets) 8 pp UV (95 ethanol) nm max 303 (6 20,100)

MS (70 eV) 1M 207.

2,6,6-Trimethyl- 1 3-hydroxy-butan- 1 -oyl ]-cyclohex- 1 -ene a. by catalytic hydrogenation 4.2 g of diketone prepared as described above in 75 ml of ethanol were subjected to a hydrogenation according to the procedure described in Example 1. There were thus obtained 4.0 g of the desired hydroxyketone (yield 95 b.p. about 75/0.01 Torr; n 1.4883; (1 0.9968

IR 3450, 1690 cm NMR: 1.07 (6H, s); 1.10 (31-1, d, J=7 cps); 1.56 (31-1, s); 4.1 (1H, m) Sppm MS: 1V1 210 (5); m/e: 192 (18); 177 (36); 166 (8); 171 (100); 135 (15); 123 (98); 109 (18); 91 (10); 81 (48); 69 (26); 55 (12); 43 (63); 29 (14).

b. by reduction by means of LiAl1-1 By proceeding as indicated in Example 1 and starting from the diketone prepared as described in that same Example there will be obtained 2,6,6-trimethyl-1[3- hydroxy-butan-l-oyl]-cyclohex-l-ene in a yield of 30-40 2,6,6-Trimethyll 3-hydroxy-butan- 1 -oyl]-cyclohex- 1-ene can be converted into 2,6,6-trimethyl-[but-2-enl-oyl]-cyclohex-1-ene according to' the procedure given in Example 1 for the conversion of the corresponding cyclohex-Z-ene derivative. In this case, however, toluene was used as the solvent, and the cyclization was carried out at about l1 10.

The analytical data were identical with those of a pure sample prepared according to one of the known methods [cf. Swiss Pat. No. 505,773].

In accordance with the procedure described in Examples 1 and 2, the following compounds were prepared:

2,6,6-Trim ethyl- 1 2-methy1- 1 ,3-dioxo- 1 -but- 1 -yl]- cyclohex- 1 -ene IR 1700 and 1600 cm NMR 0.86 and 0.94 (6H, s); 1.28 (3H, d, J=8 cps); 1.59 (3H, s); 5.48 (11-1, m) 8 ppm MS M 222 (5); m/e: 207 (0.1); 165 (0.5); 150 (36); 135 (5); 123 (72); 107 (18); 99 (100); 81 (33); 67 57 (14); 43 (76); 27 (7).

2,6,6-Trimethyl-1-[2-methyl-1,3-dioxo-1-but-1yl]- cyclohex-2-ene IR 2800 and 1580 cm NMR 0.95 and 1.14 (6H, 2s); 1.56 (3H, s); 1.71 (3H, s); 2.12 (31-1, s) 8 ppm MS M 222 (5); m/e: 207 (100); 191 (1); 179 (l); 165 (10); 151 (20); 139 (13); 123 (16); 109 (8); 99 (16); 81 (12); 67 (5); 55 (10); 43 (40); 27 (6).

Z-Methylene-6,6-dimethyl-1-[2-methyl-1,3-dioxo-lbut- 1y1]-cyclohexane IR 3080, 1725, 1690, 1640 and 900 cm NMR 0.9 (61-1, s); 1.2 (31-1, d, J=7 cps); 2.05 (31-1, s); 4.7 and 4.86 (2H, 2m) 5 ppm MS M 222 (l); m/e: 207 (2); 193(1); 179(6); 150 (60); 135 (32); 123 (52); 107 (17); 99 (40); 81 (38); 69 (16); 55 (16); 43 (100); 27 (9).

2-Methylene-6,6-dimethyl-1-[ 1,3-dioxol -but- 1 -yl]- cyclohexane 1R 3080, 2600, 1640, 1610, 890 cm NMR 0.9 and 0.98 (6H, 2s); 1.96 (31-1, s); 4.65 and 4.77 (2H, 2m); 5,34 (31-1, s) 6 ppm The starting materials for the above preparations were prepared as follows:

for 2,6,6-Trimethyl-1-[2-methyl-1,3-dioxo-l-butyl]- cycloh ex- 1 -ene:

a. 16 g of hydroxylamine hydrochloride in 60 ml of water were added to a solution of a-isomethyl ionone (41.2 g; 0.200 mole) in ethanol, kept under vigorous stirring. 22 g of sodium hydrogenocarbonate were then added to the said solution in small portions and the thus obtained mixture was refluxed for 24 hours. After cooling, the said mixture was poured into 250 m1 of water, extracted with ether (750 ml) and with methylene chloride (130 ml). The combined organic extracts were dried over magnesium sulphate and concentrated under reduced pressure to give 43.6 g of the desired oxime. There were obtained 41.1 g of a-isomethyl ionone oxime (yield 93 b.p. 1 101 12/0.05 Torr, by fractional distillation.

1R (CHCl 3560, 3250, 2900, 1630 cm NMR (CDCl 0.79 (31-1, s); 0.92 (3H, s); 1.53 (3H, m); 1.94 (3H, broad band, 5); 2.06 (31-1, 5); 2.66 (11-1, d, J=10 cps); 5.41 11-1, m); 5.69 (1H, d ofq, J=10,0.5 cps); 9.85 (11-1, broad band); 1.2-2.2 (4H, multiplets) 8 ppm UV (95 ethanol) nm max 236 (6 22,800)

MS (70 eV) M 221.

b. A solution of sodium hydrogenocarbonate (4.50 g) in 25 ml of water was added, while stirring, to a solution of a-isomethyl ionone oxime (2.42 g; 0.011 mole) in 30 ml of tetrahydrofuran.

The process was the carried on in the absence of light, and a solution of potassium iodide (5.80 g) and iodine (2.84 'g; 0.011 mole) in 15 ml of water was added. After having been refluxed for 18 hours, the reaction mixture was poured into a concentrated solution of sodium bisulphite ml), extracted with ether m1), and the organic extracts were dried over so dium sulphate and concentrated under reduced pressure. The fractional distillation of the obtained residue yielded 1.380 g of 3,4-dimethyl-5-[2 ,6 ,6-trimethylcyclohex-2-en-l-yl]-isoxazole (yield 57 b.p. 7274/0.04 Torr.

1R (CI-ICl 2910, 1620, 1440, 1414 cm NMR (CDCl 0.72 (3H, s); 1.00 (31-1, s); 1.50 (3H, m); 1.90 (3H, s); 2.14 (31-1, s); 2.96 (1H, broad band, s); 5.63 (1H, m); 1.2-2.2 (41-1, multiplets) 8 ppm UV (95 ethanol): nm max 225 (68150) MS (70 eV) M 219.

0. By a treatment of the thus obtained isoxazole according to the procedure described in Example 1, paragraph c, there was obtained 2,6,6-trimethyl-l-[3- amino-2-methyl-but-2-en-1-oyl]-cyclohex-2-ene.

for 2-methylene-6,6-dimethyll 1,3-dioxo1-butyl]- cyclohexane:

a. A solution of 30 g of 'y-ionone in 75 ml of ethanol was added to a solution of hydroxylamine hydrochloride (12 g) and sodium acetate (21.6 g) in 30 ml of water. The addition was completed within 5 minutes. The reaction was slightly exothermic, the reaction mixture was stirred for 30 minutes, then it was concentrated under reduced pressure. Thereafter 30 ml of water and 30 ml of ether were added to the said mixture, and it was extracted with petroleum-ether. After drying and concentration, the combined organic extracts yielded a thick oil (31.2 g). An aliquot was distilled in a small distillation tube at a temperature of 180 and a pressure of 0.001 Torr. There was thus obtained a pure product which, as shown by vapour phase chromatography, constituted a mixture of the 'y-ionone oxime in the form of the two synand anti-isomers in a ratio of 20:80.

IR 3250, 1640, 980, 888 cm NMR: 0.85 and 0.92 (6H, 2s); 2.01 (3H, s); 4.54 and 4.72 (2H, 2m); 6.1 (2H, d, J= cps) 8 ppm MS:M =207(0.1);m/e: 191 (1); 176(3); 159(2); 148 (1); 136 (3); 123 (4); 107 (3); 91 (2); 81 (3); 69 (3); 58 (20); 43 (100); 27 (38).

b. A solution of sodium hydrogenocarbonate (13.6 g) in 230 ml of water was added to a solution of y-ionone oxime (8.5 g) in 150 ml of tetrahydrofuran.

The process was then carried on as indicated in Example 1 by adding to the above mentioned solution a solution of potassium iodide (23.5 g) and iodine (10.9 g), whereupon the solution was refluxed for 4 hours. After cooling the solution was extracted with petroleum-ether. After the usual treatment of drying and evaporation of the volatile portions the combined organic extracts yielded 8 .4 g of crude product which, by fractional distillation, gave 6.0 g of the desired isoxazole in the form of a yellowish oil. B.p. 130/0.001 Torr. The analysis carried out by means of a sample obtained by vapour phase chromatography (Carbowax column, 3 m, 180) showed that the obtained product was constituted by two substances in a ratio by weight of 80:20, the main product being 3-methyl-5-[2-methylene-6,6-dimethyl-cyclohexy1]-isoxazole.

1R 3080, 1640, 1590, 890 cm NMR 0.92 (61-1, 25); 2.21 (3H, s); 3.3 (11-1, 5); 4.58 and 4.76 (2H, 2m); 5.75 (1I-I,s) 8 ppm MS M 205 (23); m/e: 190 (13); 177 (25); 162 (8); 149 (10); 137 (100); 122 (10); 108 97 (13); 82 (15); 69 (63); 55 (13); 41 (50); 27 (38).

c. 4.1 g of 3-methyl-5-[2-methy1ene-6,6-dimethylcyclohexyl1-isoxazo1e in 10 m1 of anhydrous ethanol were subjected to a hydrogenation in the presence of a small amount of Raney nickel and of KOI-I. After absorption of 440 ml of hydrogen (corresponding to about 90 of the theoretical amount) the solution was filtered, washed until neutrality and concentrated to yield an oily residue (4 g). By separation by means of vapour phase chromatography (Carbowax column,

1.5 m) there was obtained in a yield of 80 2-methylene-6,6-dimethyl-1-[3-amino-but-2-enoy1]-cyclohexane.

IR 3400, 1620, 888 cm MS M 207(3);m/e: 163(1); 150(1); 136(2); 123 (2); 109 (3); 93 (3); 84 (100); 69 (8); 55 (3); 41 29 2,6,6-Trimethyl-1-[2-methyl-1 ,3-dioxo-1-butyl]- cyclohex-l-ene can be synthetized by methylation of the corresponding 2,6,6-trimethyl-1-[ 1 ,3-di0xo-1- butyl]-cyc1ohex-1-ene according to the alkylation techniques conventional in the art (e.g.: by means of CH I in the presence of NaOCl-I Similarly, 2-methy1ene-6,6-dimethyl-l-[2-methy1- 1,3-dioxo-1-butyl]-cyc1ohexane can be obtained from the corresponding 2-methy1ene-6,6-dimethy1-1-[ 1,3- dioxo-1-buty1]-cyc1ohexane.

According to the conventional techniques (see abovegiven scheme B) the following compounds were prepared:

16 2,6,6-Trimethyl-1-[2-methyl-3-hydroxy-butan-1-oy1]- cyclohex-2-ene n 1.4895; d 1.005; 5 IR: 3450, 1705, 815 cm";

NMR 0.91 and 1.1 (6H, 2 s); 1.6 (3H, s); 4.0 (1H, m); 5.5 (11-1, m) 8 ppm MS: M 224 (O); m/e: 206 (0.1); 180 (22); 165 (1); 151 (l); 137 (1); 123 (100); 101 (8);91 (14); 81 10 (54); 67 (12); 57 (89); 41 (20); 29 (33).

2,6,6-Trimethyl-1-[2-methyl-1 ,3-dihydroxy-but-l-yl1- cyclo-hex-2ene IR 3400 cm';

NMR 0.87 and 0.93 (6H, 1.8(31'1, s);4.0(1I-I, m); 5.5 (1H,m) 8 ppm MS M 226 (0); m/e: 180 (0.1); 159 (5); 124 (33); 109 (100); 93 (10); 81 (22); 67 (19); 57 43 2O 29 2,6,6-Trimethy1-1-[2-methy1-1 ,3-dihydroxy-but-1-yl1- cyclohex- 1 -ene 2-Methylene-6,6-dimethyl- 1 -[2-methyl-3-hydroxybutan-1-oyl1-cyclohexane n 1.4939; d 0.9974; IR 3450, 3080, 1700, 1640, 885 cm NMR 0.9 and 0.96 (61-1, 2s), 3.8 (1H, m); 4.78 and 4.88 (2H, 2m) 6 ppm MS M =224 (0.1); m/e: 303 (0.1); 180 (10); 165

2,6 ,6-Trimethy1- 1 1 ,3 -dioxo-but-1-yl]-cyclohexane IR: 1720, 1690, 1600 cm NMR 0.751.3 and 1.8-2.1 6 ppm;

MS: M =224(2);m/e: 209(1); 192(1); 181 (1); 163 (4); 152 (20); 141 (6); 125 (60); 109 (12); 99 (40); 83 (36); 69 (100); (30); 43 (55); 29 (20).

2,6,6-Trimethyl-1-[ 1,3 -dihydroxy-but-1-yl]-cyclohexane IR 3400, 815 cm;

NMR 0.85 and 0.99 (61-1, 25); 1.1 (3I-I, d, J=7 cps); 1.75 (3H, s); 5.35 (ll-1, m) 8 ppm;

MS: M =212(0);m/e:205 (5); 194(6); 176(3); 161 (4); 149 (24); 138 (6); 123 109 94 (50); 81 (67); 71 (50); 55 (48); 43 (98); 29 (34).

EXAMPLE 3 Perfume composition of the Chypre type A perfume composition of the Chypre type was obtained by mixing the following ingredients (parts by weight);

Bergamot Sweet orange oil Synthetic neroli Synthetic rose Synthetic jasmin Ylang extra Methylionone Hydroxycitronellal Santal oriental Patchouli Vetyveryl acetate Natural dcgreascd civet. 1O Labdanum ciste absolute, 10 70* Musk ketone 1,1-Dimethyl-6-tert-butyl-4-acetylindane Coumarin Trichloromethylphenylcarbinyl acetate Tarragon, 10 70* Oak moss absolute, 50 Benjoin resinoid. 10 Cinnamic alcohol of styrax Jasmin absolute Rose absolute Cyclopentadecanolide, 10 Methylnonylacetic aldehyde Diethyl phthalate Total O r -rrr OKIILII lJIUIlII By adding to 99.0 g of this mixture 1.0 g of a solution of 2,6,6-trimethyl- 1 1,3-dioxo-but-l-yl1- cyclohex-Z-ene a more powerful composition than the basic composition is obtained. The new composition moreover possesses a more natural character that the basic composition and an olfactive note of a herb-like type reminiscent of aromatic plants such as marjoram. in ethyl phthalate By replacing in the present Example 2,6,6-trimethyl- 1-[ 1,3-dioxo-but-l-yl]-cyclohex-2-ene by 2,6,6- trimethyll 1,3-dioxo-butl -yl]-cyclohexl-ene,

2,6 ,6'trimethyl- 1 3-hydro xy-butanl -oyl l-cyclohex- 2-ene or 2-methylene-6,6-dimethyll 1,3-dioxo-but-lyl]-cyclohexane, similar effects, although less pro nounced, were observed. In particular, by using 2,6,6- tri-methyll 2-methyll ,3 -dioxo-but-l -yl]-cyclohex- 2-ene in the proportions indicated above, a composition having a rather marked herb-like character was obtained. The fragrance of the new composition was reminscent of the odour of certain tobaccos and moreover possessed an animal note of a slightly musk-like character.

EXAMPLE 4 Flavouring composition of the Tutti-Frutti type A flavouring composition of the Tutti-Frutti type is prepared by mixing the following ingredients (parts by weight) Vanillin 20 Allyl caproate 10 Citral 2O Amyl butyrate 35 Orange oil 45 Ethyl butyrate Ethyl acetate 185 Amyl acetate 185 Lemon oil 415 Total 990 By the addition of 10 g of 2,6,6-trimethyl-l-[l,3- dioxo-but-l-yl]-cyclohex-2-ene to 990 g of the above mixture at test composition is obtained. The check composition is prepared by the addition of 10 g of lemon oil to the above mixture.

The foodstuffs described below are flavoured by using the proportions indicated (per kg of foodstuff) by means of the test and check compositions:

Cake 20 g Custard 5 10 g Candy 15 20 g Candy: A mixture of 100 ml of sugar syrup (prepared by dissolving 1 kg of sucrose in 600 ml of water) and 20 g of glucose is slowly heated to C. The flavour is added thereto, and it is allowed to harden while coolmg.

Custard: A mixture of 60 g of sucrose and 3 g of pectin is added to 500 ml of warm milk, while stirring. The mixture is heated to the boil for a few seconds, the flavour is added, and the whole is allowed to cool.

Cake: The following ingredients are intimately mixed: 100 g of vegetable margarine, 1.5 g of NaCl, 100 g of sucrose, 2 eggs and 100 g of flour. The flavour is added, and the mass is cooked in the oven for 40 minutes at C.

The finished foodstuffs are subjected to a panel of experts who have to express their opinions as to the value of the samples. All the members of the group were in agreement, when stating without any hesitation, that the taste of the test samples was more rounded-off than that of the check samples and that at the same time it had a floral, woody, camphor-like character. The camphor-like note is reminiscent of turpentine or the taste of certain berries such as bilberries.

By replacing in the above Example 2,6,6-trimethyl-l- [1,3-dioxo-butl-yl]-cyclohex-2-ene by 2,6,6-trimethyl-l-[ l,3-dioxo-but-l-yll-cyclohex-l-ene the corresponding test samples have an analogous organoleptic note. Similar, but less pronounced effects, were obtained by the use of 2,6,6--trimethyl-1-[3-hydroxybutan-l-oyll-cyclohex-2-ene or 2,6,6-trimethyl-l-[3- hydroxy-butaiv 1 -oyl ]-c yclohexl-eue.

The compounds of formula 11 used as starting materials in the process of this invention can be prepared according to the synthetic method described in U.S. copending application Ser. No. 343,490 tiled in the U.S. Pat. Office on Mar. 21, 1973. The above application is entitled New Nitrogen Derivatives, their Use and Process for Preparing same, the inventors are George Hermann Buchi and John Christopher Vederas. This copending application is assigned to the same assignee as this application.

For example, a compound of the formula II can be prepared by reacting a compound of formula wherein the dotted lines as well as the symbols R R R R and R have the same meaning as aforeindicated, with a halogen, e.g. iodine or bromine, or with a donor of positive halogen, e.g. N-bromosuccinimide to provide an isoxazole derivative of formula upon which catalytic hydrogenation yields the amino derivatives of formula ll.

The nitrogen derivatives used as starting materials in the above mentioned process can be prepared by reacting afi-unsaturated ketones of formula 2213 (1947); idem, 30, 2216 (1947); Fortschritte der Chemie organischer Naturstoffe, Vlll, 146 (1951); J. Chem. Soc., 1074 (1951); J. Org. Chem., 32, 180 (1967). Some of the said components are commercially available.

The formation of the isoxazoles is preferably effected by means of iodine. This latter is maintained, at least partially, in solution in an aqueous medium by the addition of an alkali metal iodide, e.g. potassium iodide.

The cyclization reaction is preferably performed in an aqueous medium in the presence of an inert organic solvent such as alcohol, e.g. methanol, ethanol, npropanol or iso-propanol, or in the presence of an ether, e.g. ethyl ether, dioxan, tetrahydroguran, monoglyme or diglyme. Methyl alcohol or tetrahydrofuran are preferred.

The said cyclization may occur in a wide temperature 65 range. The formation of the desired isoxazole was observed at temperatures from 25 to C. However, it is preferred to operate at temperatures higher than those aforeindicated. Indeed, it has been found that the best yields of final product were obtained when the cyclization was effected at the boiling temperatur of the chosen solvent or at a temperature in the vicinity thereof. Of course. higher temperatures can also be used, in particular when the operation is curried out at a pressure exceeding the atmospheric pressure.

The reaction time can also vary within a wide range. Thus, if the reaction is carried out at a temperature from about to about C, good yields of final product are obtained within a reaction time comprised between about 1 hour and about 24 hours. Generally 2 /2 hours are sufficient for the complete conversion of the compounds of formula into their cyclic derivatives. As mentioned above, the reaction is preferably carried out in a neutral or alkaline medium. pH Values comprised between about 7 and about 12 can be conveniently used. In order to attain and to maintain in the course of the reaction this preferred acidity a buffer can be used, e.g. a boric or phosphoric salt of an alkali metal, e.g. sodium tetraborate, or sodium or potassium monoor dihydrogenophosphate, or sodium hydrogenocarbonate. For reasons of economy the last mentioned buffer reagent is preferred.

When iodine is used as the cyclizing agent, the reaction is preferably carried out in the absence of light; however, this condition is not essential.

Working examples of how these compounds can be prepared are set forth in the specific examples given above.

I claim:

1. Compounds of the formula wherein the ring contains one double bond in position 1 or an exocyclic bond at position 2, R and R both represent hydrogen or one of them represents a lower alkyl containing from 1 to 6 carbon atoms and the other hydrogen, R, R and R all represent hydrogen or one of them represents a lower alkyl containing from 1 to 6 carbon atoms and the others hydrogen.

2. 2,6,6-Trimethyll l ,3-dioxo-butl -yl]-cyclo-hexl-ene.

3. 2,6,6-Trimethyl-l -[2-methyl-l ,3-dioxo-but-l-yl1- cyclohexl-ene.

4. 2-Methylene-6,6-dimethyl-l-[2-methyl-l ,3-dioxobut- 1 -yl cyclohexzme.

UNITED STATES PATENT AND TRADEMARK OFFICE CERTIFICATE OF CORRECTIQN 9 PATENT NO. 3,923,896

DATED December 2, 1975 INVENTOR(S) Karl-Heinrich Schulte-Elte It is certified that error appears in the above-identified patent and that said Letters Patent Q are hereby corrected as shown below:

Column 10, lines 38-39, delete "The solution wasthen subjected to a hydrogenation.".

Column 13, line 38, "-1-but-lyl]-" should be ---1-bu1;-1- 1]---.

Column 16, line 11, "cyclo-hex-Zene" should be cycloheX-2-ene-.

Column 17, line 8, "79 I (44)" should be --79 (44)--.

Column 18, line 49, "test samples" should be --"test" samples--. r

Engncd and gealcd thus eighteenth Day Of May 1976. [SEAL] A Arrest.

RUTH c. MASON c. MARSHALL DANN Arresting ()fj'r'cer (ummissiunvr ufPatems and Trademarks 

1. COMPOUNDS OF THE FORMULA
 2. 2,6,6-Trimethyl-1-(1,3-dioxo-but-1-yl)-cyclo-hex-1-ene.
 3. 2,6,6-Trimethyl-1-(2-methyl-1,3-dioxo-but-1-yl)-cyclohex-1-ene.
 4. 2-Methylene-6,6-dimethyl-1-(2-methyl-1,3-dioxo-but-1-yl)cyclohexane. 